Question: Which flammable liquid has the highest ionization energy ?
Paraphrase: Name the combustable fluid with the most ionization work.
SPARQL (Wikidata): select ?ent where { ?ent wdt:P31 wd:Q5457310 . ?ent wdt:P2260 ?obj . ?ent wdt:P31 wd:Q21073026 } ORDER BY DESC(?obj)LIMIT 5